-LRB- CNN -RRB- -- Thousands of Ontario , Canada , residents made do without power Monday in the aftermath of storms that toppled trees and brought down power lines . Meanwhile , residents in the upper Midwest prepared for bitter cold wind chills .

More than 300,000 customers remained without electricity Monday across Ontario , including 200,000 in Toronto , officials reported , in the wake of what Mayor Rob Ford called one of the worst ice storms to hit the city .

Still , the city was functioning and conditions were `` not even close '' to warranting an emergency declaration , he told reporters Monday .

Toronto Hydro CEO Anthony Haines said major power lines are being restored at a rate of one every few minutes , but street-to-street work remains , and he could n't offer a guarantee everyone will have power by Christmas .

`` My caution continues to be my caution . Let 's really plan for the worst , '' Haines said Monday evening . `` I am encouraged in the progress we have made today , obviously , with well over 100,000 customers being restored today . ''

Ford said 100 trucks from other cities were on their way to Toronto to help restore power to more people .

Toronto had opened more than a dozen warming centers some were expecting up to 300 people , officials said .

In the United States , areas that had been as warm as the 70s on Sunday began a slide into frigid territory as Canada sent some of that cold air sliding across the eastern United States .

Dangerously cold wind chills were on tap in parts of Kansas , Nebraska , South Dakota , North Dakota , Minnesota , Iowa , Missouri and Illinois . Wind chill warnings were posted for parts of Minnesota , warning of of wind chills as low as 45 below zero .

Still , the picture was much calmer than over the weekend , when storms left at least 10 people dead .

At least five people died in Kentucky floodwaters , two people died in Mississippi storms , and one person died in a traffic accident during Missouri 's severe weather , officials said . A weather-related wreck Saturday near Wichita , Kansas , left one person dead , according to CNN affiliate KWCH-TV . And a tornado Saturday also killed a woman in Arkansas , CNN affiliate KARK-TV in Little Rock reported .

The tornado was one of two rated at EF2 to hit the state on Saturday .

Northeast : Hot and cold

New York City set a record high Sunday at 71 degrees , National Weather Service meteorologist Ashley Sears said . The previous record , set in 1949 and matched in 1998 , was 63 .

But temperatures will fall each day until Wednesday , and by Christmas , New York might not even reach the freezing mark .

And in northern New England , another round of snow and ice is set for Monday , the National Weather Service said .

Southeast : When it rains , it pours

Rain was finally tapering off in Georgia , South Carolina and states in the Mid-Atlantic . A wave of cold temperatures will take its place Tuesday . Temperatures will likely be 10 to 15 degrees colder than normal on Christmas Eve and Christmas Day .

Midwest : Ice and dangerous wind chills

The storms left some Michigan residents dealing with no electricity . Sara Hadley 's family lost power after an ice storm struck her hometown of Lansing . She sent photos of some of the countless icicles in her neighborhood .

`` Last time we had ice like this was 1998 , '' Hadley told CNN 's iReport .

Pacific Northwest : Another storm brewing

Coastal and valley rain as well as mountain snow is in the forecast through Tuesday , the service said .

Higher elevations could get dumped with 6 to 12 inches of snow .

CNN 's Sean Morris , Adam Shivers , Todd Borek , Jareen Imam , Leslie Holland and Janet DiGiacomo contributed to this report .

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NEW : Power restored to 100,000 customers in Toronto , electric company official says

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Blowing snow and dangerous wind chill temperatures will hit the Upper Midwest

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New York City will get steadily colder after reaching a record-breaking 71 degrees on Sunday